The invention relates to a backrest structure for strollers that is movable synchronously with the stroller frame and adjustable angularly in multiple stages.
Strollers (infant carriers) are generally designed with a collapsible function to facilitate carrying and storage. Many folding features have been developed over the years to enhance operation effectiveness. For instance, U.S. Pat. No. 5,454,584 discloses a collapsible stroller that has a frame movable between a collapsed position and an operating position. It has a back movable between a first position (sitting position) and a second position (recumbent position). A latch means is provided between the frame and the back that includes a boss in a rear leg tube and a slot on a latch. The boss may be positioned within the slot to keep the back at the first position. The latch means, back and frame are so designed that when the back is at the first position, the frame may be moved from the operating position to the collapsed position, and when the boss is separated from the slot, the latch means automatically releases the back to allow the back to move (drop) automatically to the second position. Hence users do not need to release the back separately to fold the stroller. Although the cited patent claims it enables the back to move (drop) automatically when the stroller is folding, the boss cannot always overcome the friction between the slot and the boss and separate smoothly from the slot. As a result, the back does not always move automatically as desired. Thus users have to release the back separately to fold the stroller. There is a need to design an improved backrest mechanism to fold the back effectively and safely.
The primary object of the invention is to provide a backrest structure that has a linkage bar between the frame and the backrest so that the backrest may be folded or extended synchronously with the collapsing or extension of the frame. The backrest structure maintains the stability of the backrest while the stroller is moving to improve the safety of the infant.
Another object of the invention is to provide a backrest adjusting means to enable the backrest to interact with the linkage bar and provide multiple stages of adjustment for the angle of the backrest to enhance comfort for the infant.
According to the invention, the stroller includes a frame movable between a sitting position and a collapsed position and a loading rack having an anchor section, which has a portion for seating the passenger. The backrest structure of the invention includes a backrest adjusting means that is pivotally mounted on the anchor section, a movable backrest that is pivotally engaged with the backrest adjusting means and is movable between a first position and a second position when the frame is at the sitting positionxe2x80x94with the passenger sitting generally upright when the backrest is at the first position and lying rearwards when the backrest is at the second positionxe2x80x94and a linkage bar with a first end pivotally engaged with the frame and a second end pivotally engaged with the backrest adjusting means. When the frame is at the sitting position, the linkage bar supports the backrest adjusting means and the backrest at the first position. When the frame is moved from the sitting position to the collapsed position, the frame moves the linkage bar and pushes the backrest adjusting means to make the backrest turn synchronously with the frame and fold at the second position to enable the stroller be folded smoothly. In addition, when the frame is at the sitting position, the backrest adjusting means may be adjusted in multiple stages to alter the angle of the backrest to suit the passenger""s requirements.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.